Hi there!
Voltage in a series can be expressed by the following:

In words, the total voltage is equal to the sum of the individual voltage drops in a SERIES circuit.
We can solve for the total voltage:

You can find the mass of an atom by adding the number of protons and neutrons. In this case the atom has 2 protons and 3 neutrons so the mass is 5.
Answer:
A
Explanation:
Let the x represent the amount of heat generated from the fossil fuel.
88% of x = 0.88 x
0.88 x was used to convert water to steam.
heat carried by steam = 40% × 0.88 x = 0.352 x
efficiency of the heat -to- work conversion = work output / work input = 0.352 x / x = 0.352 × 100 = 35.2 % which is less than 40 %